package daily import ( "crypto/md5" "crypto/rand" "encoding/base64" "encoding/binary" "fmt" "log" "os" "time" "github.com/pagefaultgames/pokerogue-server/db" "github.com/robfig/cron/v3" ) const secondsPerDay = 60 * 60 * 24 var ( scheduler = cron.New(cron.WithLocation(time.UTC)) secret []byte ) func Init() error { var err error secret, err = os.ReadFile("secret.key") if err != nil { if !os.IsNotExist(err) { return fmt.Errorf("failed to read daily seed secret: %s", err) } newSecret := make([]byte, 32) _, err := rand.Read(newSecret) if err != nil { return fmt.Errorf("failed to generate daily seed secret: %s", err) } err = os.WriteFile("secret.key", newSecret, 0400) if err != nil { return fmt.Errorf("failed to write daily seed secret: %s", err) } secret = newSecret } err = recordNewDaily() if err != nil { log.Print(err) } log.Printf("Daily Run Seed: %s", Seed()) scheduler.AddFunc("@daily", func() { err := recordNewDaily() if err != nil { log.Printf("error while recording new daily: %s", err) } }) scheduler.Start() return nil } func Seed() string { return base64.StdEncoding.EncodeToString(deriveSeed(time.Now().UTC())) } func deriveSeed(seedTime time.Time) []byte { day := make([]byte, 8) binary.BigEndian.PutUint64(day, uint64(seedTime.Unix()/secondsPerDay)) hashedSeed := md5.Sum(append(day, secret...)) return hashedSeed[:] } func recordNewDaily() error { err := db.TryAddDailyRun(Seed()) if err != nil { return err } return nil }